(1) Field of the Invention
The present invention relates to a water craft or water-borne vehicle such as a small water craft, particularly of the jet propulsion-type water craft, and to a method of self-righting said water craft to normal upright position, when it has been overturned.
(2) Description of the Prior Art
The small water craft and the like may be operated at high speed and in sharp turn. As a result, the operator can enjoy a thrill at the high speed driving and in the sharp turn, but has the operational unstable condition when it is put in a sharp turn, and as a result it overturns.
As shown in FIGS. 1a, 1b and 1c, a conventional water craft of this type includes a hull 1 and an enclosed engine room 4 at a forward end, which is closed by a cover 3. The engine room 4 thus forms a float or buoyant body adjacent the bow 2. In FIG. 1b it will be seen that the center of gravity G of said float, and the center of buoyancy B of said float in FIG. 1c, and in the event the water craft overturns in the water. The center of buoyancy B is designed to be as high as possible, but the center of gravity G to be as low as possible. This arrangement so designed increases a vertical distance D between these centers B and G on a vertical center line L--L of the water craft, and as a result, the float is located at an upward portion of the bow 2, so that in the above conventional water craft, this bow 2 was made too bulky and stubby shaped. Thus, it has been a question that the shape of water craft can not be formed as a streamlined shape promoting a sporty and speedy impression.
As shown in the above, in the conventional water craft, the center of buoyancy B and the center of gravity G are located on the vertical center line L--L of the water craft, so that it is difficult for self-righting to the normal upright position quickly, when the water craft was overturned in the water. Furthermore, if a weight or ballast is added to a bottom of the water craft, the total weight is increased, so that the water craft is difficult to transport, which is an important factor for a small recreational water craft.